Cervical lymph node metastatic carcinoma accounts for about 3/4 of the total number of neck malignant tumors; among neck masses, the incidence rate is second only to chronic lymphadenitis and thyroid disease. The vast majority (85%) of primary cancer foci are in the head and neck, especially nasopharyngeal carcinoma and thyroid cancer metastasis is the most common. The primary cancer foci of supraclavicular fossa metastatic tumors are mostly in the chest and abdomen (including lungs, mediastinum, breasts, gastrointestinal tract, pancreas, etc.); but the cervical lymph node metastasis of gastrointestinal tract and pancreatic cancer mostly occurs in the left supraclavicular fossa through the thoracic duct. It must be noted that in many patients with head and neck malignancies (such as nasopharyngeal carcinoma and thyroid cancer), metastatic tumors in the lateral neck area are often the first major symptom; on the contrary, the primary cancer foci are often very small. The patient himself does not feel it, and it is even difficult to find it during examination. Therefore, a comprehensive and detailed examination must be carried out to make a clear diagnosis.